Micaiahfied

I guess I never asked this. I have only ever dynoed 1 time. The operator said to bring the truck to 1500rpm, let it level off, and then floor it... what do you guys think of this?

What rpm should peak HP be?
What rpm should peak torque be?

my peak torque is around 2300, is that too high?

Thanks

GLHS

Yes, floor it.

Micaiahfied

bump, anyone else?

Bob Beauchaine

Depends on the dyno. 1500 RPM then floor it is a good general rule of thumb. There are some tricks that will give you a 15 to 20 RWHP increase but some operators wont let you use them. I've seen some good numbers in direct and also in OD. I usually run 2 runs in 4th - direct, and 1 in 5th - OD.

Bob

Micaiahfied

Is there any reason that running in 5th would give inaccurate readings? I ran a couple that way to try to load the motor up a little more...
What are the tricks? and are you just fooling the computer into giving higher numbers or is it still an accurate reading?

GLHS

When tested in 4th and 5th, my truck would give identical hp but torque is always higher when run in 5th...........about 5-10% higher.
Your torque should peak sooner, maybe around 1800. Usually hp is around 2200-2500.

Bob Beauchaine

The idea behind 1500 rpms is to allow your turbo to start spooling up but, on a no load dyno such as a Dyno-jet you can't build boost at that rpms until you have some low end load. If you feather the brakes until you get somewhere between 2 and 5 psi of boost on your guage at about 1500 rpms then release the brakes and put the hammer down you will see a higher HP and torque numbers. Is this "fooling" with the numbers - not if you consider that at 1500 rpms driving down the road you have you will have a load on the engine. I would consider that dynoing this way more closely mimics actual driving conditions therefore is actually more accurate.

On a Mustang load style dyno they can put a load on the dyno itself. I personally don't like a Mustang because there is too much operator input which I feel can distort the numbers.

Hope this helps.

Bob